Biomedical Engineering and Bioengineering Commons^™

Hysteresis In Repolarization Of Cardiac Action Potentials: Effects Of Spatial Heterogeneity And Slow Repolarization Currents, Linyuan Jing

Theses and Dissertations--Biomedical Engineering

Repolarization alternans, i.e. beat-to-beat variation of repolarization of action potential, is proposed as a predictor of life-threatening arrhythmias. Restitution relates repolarization duration with its previous relaxation time, i.e. diatstolic interval (DI), and is considered a dominant mechanism for alternans. Previously, we observed that different repolarization durations at the same DI during decelerating and accelerating pacing, i.e. restitution displays hysteresis, which is a measure of “cardiac memory”.

Objective of the current study was to investigate in the pig 1) the mechanism for a previously observed hysteresis type phenomenon, where alternans, once started at higher heart rate, persists even when heart rate …